Rather than applying a single set of breast cancer screening guidelines to most women, a more individualized approach that considers risk factors such as breast density may help to balance the benefits and costs of screening. These results were published in the Annals of Internal Medicine.
A mammogram is an X-ray of the breast. A screening mammogram is a mammogram that is performed in a woman without breast symptoms. The goal of screening mammography is to detect breast cancer at an early stage when it is most easily treated.
Different groups of experts have reached different conclusions about when mammographic screening should begin and how often it should be performed. The U.S. Preventive Services Task Force recommends that routine screening of average-risk women begin at age 50 and be performed every two years. The American Cancer Society recommends annual screening beginning at age 40.
An alternative approach to screening is to make more individualized decisions based on a woman’s risk of breast cancer and her own beliefs about the risks and benefits of screening. This has already happened for women who are at very high risk of breast cancer (as a result of BRCA1 or BRCA2 gene mutations, for example), but the broader population of women may benefit as well.
One factor that has consistently been linked with risk of breast cancer is breast density. Breast density can be assessed by mammography and refers to the extent of glandular and connective tissue in the breast. Breasts with more glandular and connective tissue—and less fat—are denser. Women with high breast density are at increased risk of developing breast cancer.
To explore how factors such age, breast density, history of breast biopsy, family history of breast cancer, and screening interval influence the cost-effectiveness of breast cancer screening, researchers developed a statistical model. The following are some of the key findings of their research:
- Having a mammogram every year was not cost-effective for any group of women.
- Having a baseline mammogram at age 40 can help guide subsequent screening decisions. Women who are at increased risk of breast cancer as a result of high breast density or other factors may benefit from regular (every two years) screening in their 40s. Other women may be able to wait until age 50 for additional screening.
- A three-to-four year interval between screening mammograms may be an option for some low-risk older women.
These results do not apply to women with gene mutations that put them at high risk of breast cancer. For the broader population of women, however, it appears that a more individualized approach to breast cancer screening may be warranted. The approach suggested by this study has not yet been incorporated into widely used screening guidelines such as those from the American Cancer Society and the U.S. Preventive Services Task Force. Screening guidelines will continue to evolve, however, as new evidence becomes available.
Women who have questions about the screening approach that’s right for them are advised to talk with their healthcare providers.
Reference: Schousboe JT, Kerlikowske K, Low A, Cummings SR. Personalizing mammography by breast density and other risk factors for breast cancer: analysis of health benefits and cost-effectiveness. Annals of Internal Medicine. 2011;155:10-20.